What is a good water vapor transmission rate?
What is a good water vapor transmission rate?
Relevance to package performance
| Film Type | WVTR @ 100°F (38°C), 90% RH for 1 mil film | |
|---|---|---|
| (g/100 in2/24 hr) | (g/m2/24 hr) | |
| Biax OPP | 0.25 – 0.40 | 3.9 – 6.2 |
| HPDE (high density polyethylene) | 0.3 – 0.5 | 4.7 – 7.8 |
| Cast PP | 0.6 – 0.7 | 9.3 – 11 |
What is water transmission rate?
Definition: Water Vapor Transmission Rate (WVTR) or Moisture Vapor Transmission Rate (MVTR) is the rate at which water vapor will permeate through solid material over a specific period of time. Permeability: All polymers are permeable to gases and vapors to different extents.
How do you calculate water vapor permeability?
Water vapor transmission were measured and corrected by different calculation methods and because in this work the thickness of all films is known, the calculation of water vapor permeability is obtained by multiplying permeance by thickness.
What is GTR in food packaging?
N500 Gas permeation tests the gas transmission rate (GTR) of packaging material,Is widely used in food industry, pharmaceutical industry, flexible packaging materials industry (plastic film, barrier materials, sheets, metal aluminum,PVC sheets), university and quality institution for gas(O2,CO2,N2,etc)permeation test …
What is water vapor permeability?
Often referred to as breathability, vapor permeability describes a material’s ability to allow water vapor to pass through it. Unlike bulk water holdout, which refers to water in its liquid form, vapor permeability concerns water in its gas form.
What is WVTR and OTR test?
Oxygen and Water Vapour Permeability Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are two key material specification properties which determine the shelf life of food packaging. Smithers offers a full range of barrier testing services, including an inter-laboratory proficiency scheme.
What is vapor transmission test?
Moisture vapor transmission rate (MVTR), also water vapor transmission rate (WVTR), is a measure of the passage of water vapor through a substance. It is a measure of the permeability for vapor barriers. There are many industries where moisture control is critical.
What is a good water vapor permeability?
Unlike bulk water holdout, which refers to water in its liquid form, vapor permeability concerns water in its gas form. Current building codes require the minimum measure of permeability to be around 5 perms.
What is water permeability material?
Energy Materials Moisture permeability is the material’s resistance to the water vapor diffusion through a unit of surface area. This can be experimentally determined using one of two methods, as described in ASTM standard E96M-15 [34]. The two methods are the desiccant method and the water method.
What is gas transmission rate?
Gas Transmission Rate (GTR): The quantity of a given gas passing through a unit of the parallel surfaces of a plastic film in unit time under the conditions of test. The SI unit of GTR is 1 mol / (m2·s).
What is a good oxygen transmission rate?
OTR values are used to compare the relative oxygen barrier capabilities of packaging films. An industry rule-of-thumb is that a material is considered a “high oxygen barrier” if its OTR is less than 1 cc/100 in2/24 hr (15.5 cc/m2/24 hr).